A clothing dryer frame can be provided with a star-shaped array of main arms which are swingable outwardly from a closed position of the frame and wherein the main arms are spanned by cords or the like to support laundry to be dried. Umbrella frames, especially for garden umbrellas can have main arms spanned by a canopy. Such frames are characterized by an arrangement in which the star-shaped two members on the support post can be moved toward and away from one another for the opening or closing of the frame respectively.
More particularly, such a frame can comprise a tubular support post which can have a first star-shaped member axially fixable thereon and forming pivots for the main or support arms. A second star-shaped member which also can be axially fixed to the support tube can be formed with pivots for the bracing arms and, by axial shifting of one of the star-shaped members, the main and bracing arms can be swung between the closed positioning which the arms lie along the support tube, and an open position in which the arms are spread outwardly.
Between each main arm and a respective support arm, a knuckle joint is provided which is opened up upon the spreading of the arms and which is folded inwardly when the arms are closed.
In the opening of the frame, assuming that the main and bracing arms have been swung inwardly to lie generally along the post, opening or spreading of the frame is effected by moving one of the star shaped members axially along the support tube toward the other of these members until the cords or canopy are tensioned and the main arms are spread outwardly and are fixed under tension. The movable star-shaped member can then be secured on the support tube. To fold the main arms again inwardly, the axial fixation of the movable star-shaped member is released and that member is then moved away from the fixed star-shaped member until the canopy and cords are drawn inwardly and the main arms are caused to lie along the support tube. In this inwardly swung position of the arms, the movable star-shaped member can be clamped axially once again to hold the frame in its folded position. The force required to open the frame, especially when the bracing and main arms are aligned in the direction of force application, can be substantial.
The support tube or post may be vertically anchored in a base or stand in the case of a garden umbrella, or in the ground in the case of a laundry dryer. The fixed star-shaped member is usually provided at the top of the post and the movable star shaped member is spaced below the latter and can pivotally carry the bracing arms for swinging outwardly the main arms which are pivotally mounted on the upper or fixed star-shaped member.
A detent system can be provided for locking the lower star-shaped member along the support tube.
For clothing dryers or the like which are mounted in the ground, the star-shaped member to which the bracing arms are pivoted may be located above the star-shaped member to which the main arms are pivotally connected and to swing the main arms outwardly, the upper star-shaped member may be drawn downwardly toward the lower star-shaped member and locked in place appropriately along the post.
In most cases, the frame is closed until it is to be used and only then opened, whether it is permanently mounted in a vertical position or can be laid down. When, however, the dryer or umbrella is to be used to hang up laundry or protect an area from rain or sun, the frame must be swung into its open position. In practice, the opening of the frame has required considerable force even for an initial spreading of the main arms and the bracing arms outwardly. Until this initial resistance has been overcome, it is not possible to relatively move the star-shaped members easily so as to continue the outwardly spreading operation. After this initial resistance, the movement of the movable star-shaped member must overcome the weight of the arms and any canopy or cords thereon.
For laundry dryers, usually four main arms are provided and once these arms are fully swung outwardly, they must be able to carry the weight not only of the arms and the cords, but also the considerable weight of wet, heavy laundry in a stable manner. The force necessary for opening the frame in the past has, therefore, been relatively high. Furthermore, the lower star-shaped member is frequently located so close to the ground that it is difficult for the user to exercise even the initial force required to spread the main arms outwardly without awkward manipulation or bending.
Various proposals have been made to ease the outward spreading of the arms of such frames. For example, it has been proposed to connect the two star-shaped members by a cable which can run from one to the other along the support tube and can be diverted at the lower star shaped member away from the post. To swing the arms of the frame outwardly, the cable is drawn upwardly at an angle to the post and radially outwardly from the star-shaped member close to the ground. The cable eliminates the need for the operator to bend, but the significant resistance of the frame to opening is not easily overcome through the use of the cable which itself introduces a significant frictional component.
EP 113 789 B1 discloses an umbrella like laundry dryer with a star-shaped member fixed axially at the upper end of the support tube and a cable passing twice between the upper and lower star-shaped members in an effort to gain a mechanical advantage. The bracing arms are pivotally mounted on the upper star-shaped member and are radially inwardly offset with respect to the outer periphery of the support tube. The support arms themselves are of an offset nature. In this kind of system, there is indeed a facilitation of the opening operation, but the system is more expensive to fabricate and has tended to be more bulky.
U.S. Pat. No. 2,289,450 discloses another kind of umbrella shaped dryer in which, in the closed position of the frame, the knuckle joints between the support arms and the bracing arms lie outwardly of the lines connecting the pivots for the support arms at the lower star-shaped member and the bracing arms at the upper star-shaped member. The star-shaped members are comprised of two elongated sleeves which have ends turned toward one another and locked together when the arms are in their fully spread positions.
The support arms are formed with projections at their ends connected to the upper star-shaped member which project radially inwardly of the periphery of the support tube in the fully spread positions of the arms. The locking system is here comparatively complex as well.
EP 220 565 A2 describes an umbrella shaped laundry dryer which has at the upper end of the post or support tube an axially fixed second star-shaped member to which a cable is affixed while the lower star-shaped member, about which the cable passes, forms the pivots for the support arms. In this arrangement, there is a danger that the lover star-shaped member, which is free to wobble, may be jammed in use. There is also a problem here with an increasing tendency to jam with greater application of force to the cable. Finally, mention may be made of the umbrella type laundry dryer of EP 649 935 which requires that the bracing elements penetrate through openings in the support tube or post radially and which has been found to be a drawback because openings in the support posts tend to weaken the latter.